You can request that searches are limited to PDFs. These you are welcome to download, but for personal use only, and they may not be reposted or used for commercial purposes. By clicking on the dialogue that appears, you are agreeing to single, personal use, solely for scientific purposes.
PDFs of works before about 1921 or 70 years after the copyright owner's death (a specification that varies from country to country) are not subject to copyright. PDFs from publications younger than 12 years old will not be found. We store all our PDFs in this database, and some of these may appear accidentally. If you are an author or copyright owner of one of these and find this objectionable, please let us know and we will remove it from the public part of the site.
We have endeavoured to upload many old and rare works, particularly for those with restricted library facilities. If you have a PDF of such works that you are prepared to share, please let us know.
We are assuming that providing single copies for personal research is legal, although this may not be quite as simple as it seems.